vcomp/lavc: module_done

Since the commit e056d786 (2025-06-03) it needs to be called because
the parent no longer calls that.

src/video_compress/libavcodec.cpp

@@ -272,6 +272,7 @@ struct state_video_compress_libav {
                 module_register(&module_data, parent);
         }
         ~state_video_compress_libav() {
+                module_done(&module_data);
                 av_packet_free(&pkt);
                 to_lavc_vid_conv_destroy(&pixfmt_conversion);
         }